St. Hubert was picked up in Ozone Park, Queens Wednesday night. Sources told CBS 2 police tracked his cellphone and zeroed in on his location.

Police were watching St. Hubert as he walked down a residential block in Queens around 8:30 p.m. Wednesday. They spotted him use a marker to deface a stop sign at the intersection of 145th Street and 133rd Avenue in Queens, writing, “Killzz I Will Bk,” along with a smiley face and winking eye, sources told CBS 2.

Police said St. Hubert was found blocks from his own mother’s house. Investigators said he was armed with an 8-inch knife.

After the arrest, police sources told CBS 2 that St. Hubert made incoherent ramblings about the devil while in a holding cell in the police station.

Neighbor Walter Asemota ran into St. Hubert just hours before the suspect was arrested.

“I couldn’t sleep last night,” said Walter Asemota. “It was just so shocking.”

Asemota was still shaken about it on Thursday afternoon.

“He was so collected. He told me he lift weights, he eats and rests in jail,” Asemota said. “He took a walk — he was strolling casually.”

The encounter happened around lunchtime on Wednesday, Asemota said.

In the midst of a three-day manhunt St. Hubert had been given a summons Tuesday for public urination in Brooklyn 11 hours before he was identified as the suspect in Sunday’s stabbings.

His arrest Wednesday happened less than an hour after Police Commissioner Bill Bratton and Mayor Bill de Blasio named St. Hubert as a suspect and turned to the public for help in finding him.

“I want to thank everybody who has been involved in this whole ordeal from start to finish,” P.J.’s mother, Aricka McClinton, said Thursday morning. “You all didn’t rest, you didn’t eat, you didn’t sleep. You did what you had to do.”

P.J.’s father, Nicholas Avitto, said he would ask the suspect a few questions if he saw him.

“Why would you do this?” he said. “What compelled you to do this?”

Children Were Attacked In Elevator After Playing Outside

Around 6 p.m. Sunday, the children had been playing outside under adult supervision when they went upstairs to get some ice cream from P.J.’s sixth-floor apartment.

P.J. died at a hospital. Mikayla remains in critical but stable condition. Her family says she is in the Intensive Care Unit with a breathing tube and is in and out of consciousness, but responding to commands.

Investigators said St. Hubert had shaved his head since Sunday’s stabbing. He was on parole and had missed a scheduled meeting with a parole officer on Tuesday.

Police said they were able to identify St. Hubert as a suspect from DNA found on the knife used in the elevator attack.

Suspect St. Hubert Has Long Rap Sheet

Investigators say St. Hubert had been let out of prison on May 23 after serving a five-year sentence for domestic assault and attempted murder for trying to kill his ex-girlfriend.

He also has nine prior arrests, including two for assaulting police and correction officers.

Back in 2008, his own mother filed an order of protection against him. Months later, police said he punched her numerous times in the face, wrapped an electrical cord around her head and told her he was going to kill her.

“I know what he did to his mom. He was locked up for a very long time, so I was surprised to see him,” Asemota said.

After the incident with his mother, St. Hubert was eventually sent to a psychiatric facility for seven months.

St. Hubert’s mother did not answer her door Thursday night.

And as 1010 WINS’ Al Jones reported, St. Hubert’s sister told the New York Times her brother suffered from mental illness and received no treatment in prison.

“This is someone who probably had very severe mental health problems, and I don’t know why those were not caught and treated earlier,” Mayor de Blasio said.